• Asian-Australasian Journal of Animal Sciences
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• 제17권7호
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• pp.930-935
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• 2004

The present study was aimed to study the effect of aqueous extract of Tinospora cordifolia and autologous plasma on uterine infections. Buffaloes in estrus, 40 days and above postpartum were checked for uterine infections. Animals having uterine infections were randomly divided into three groups of six animals each. Buffaloes in group I, II and III (control) were given intrauterine infusion of aqueous extract of Tinospora cordifolia (3,000 mg total dose), autologous plasma (150 ml) and phosphate buffer saline (150 ml) respectively, in three divided doses, once daily for three consecutive days, starting from the day of estrus. A fourth group (IV) comprising of six buffaloes having no uterine infection was also included in the present study. Buffaloes were inseminated artificially on next estrus following treatment and confirmed for pregnancy 60 days later. Bacterial population in CVM of buffaloes in group I, II and III was significantly (p<0.05) higher than group IV. After treatment there was a significant (p<0.01) reduction in bacterial population in group I (83.496$\pm$7.755%) and group II 80.233$\pm$5.799%) than group in III 7.557$\pm$33.551%) at next estrus. There was non-significant improvement in first service conception rate (CR, 33.33%) and overall conception rate (OCR, 27.27%) in group I, in comparison to group III (first service CR-16.67%; OCR-20.0%). No significant improvement was seen in OCR (22.22%) in-group II also in comparison to group III. The improvement in group I was however, nonsignificantly lower than normal animals of group IV (First service CR-16.67%; OCR-36.33%).

• 한국산학기술학회논문지
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• 제13권1호
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• pp.431-438
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• 2012

아민 수용액을 이용한 이산화탄소 포집기술은 현재 가장 넓게 연구되는 분야이다. 전체 공정은 선택적 이산화탄소 흡수를 위한 흡수탑과 흡수제를 재생하고 고순도 이산화탄소를 얻기 위한 재생탑으로 이루어져있다. 공정 성능에 영향을 미치는 복잡한 설계 변수들이 존재하기 때문에 상업적으로 신뢰할만한 공정을 설계하기 위해서는 모델링을 통한 공정 해석과 최적화가 필요하다. 본 연구에서는 공정의 수렴문제를 고려하여 분해방법을 사용하였고, 아민계 흡수제를 이용하는 이산화탄소 포집 공정의 변수들에 대한 민감도 분석을 수행하였다. 현실적인 설계 결과를 얻기 위해 비평형 모델을 사용하였고 95% 이상의 순도로 90%의 이산화탄소를 회수할 수 있는 최적화된 공정을 설계할 수 있었다.

• 한국재료학회지
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• 제27권3호
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• pp.137-143
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• 2017

Boron-doped diamond (BDD) electrode has an extremely wide potential window in aqueous and non-aqueous electrolytes, very low and stable background current and high resistance to surface fouling due to weak adsorption. These features endow the BDD electrode with potentially wide electrochemical applications, in such areas as wastewater treatment, electrosynthesis and electrochemical sensors. In this study, the characteristics of the BDD electrode were examined by scanning electron microscopy (SEM) and evaluated by accelerated life test. The effects of manufacturing conditions on the BDD electrode were determined and remedies for negative effects were noted in order to improve the electrode lifetime in wastewater treatment. The lifetime of the BDD electrode was influenced by manufacturing conditions, such as surface roughness, seeding method and rate of introduction of gases into the reaction chamber. The results of this study showed that BDD electrodes manufactured using sanding media of different sizes resulted in the most effective electrode lifetime when the particle size of alumina used was from $75{\sim}106{\mu}m$ (#150). Ultrasonic treatment was found to be more effective than polishing treatment in the test of seeding processes. In addition to this, BDD electrodes manufactured by introducing gases at different rates resulted in the most effective electrode lifetime when the introduced gas had a composition of hydrogen gas 94.5 vol.% carbon source gas 1.6 vol.% and boron source gas 3.9 vol.%.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.58-65
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• 2011

The bacterial uranium(VI) reduction and its resultant low solubility make this process an attractive option for removing U from groundwater. An impact of aqueous suspending iron phase, which is redox sensitive and ubiquitous in subsurface groundwater, on the U(VI) bioreduction by Shewanella putrefaciens CN32 was investigated. In our batch experiment, the U(VI) concentration ($5{\times}10^5M$) gradually decreased to a non-detectable level during the microbial respiration. However, when Fe(III) phase was suspended in solution, bioreduction of U(VI) was significantly suppressed due to a preferred reduction of Fe(III) instead of U(VI). This shows that the suspending amorphous Fe(III) phase can be a strong inhibitor to the U(VI) bioreduction. On the contrary, when iron was present as a soluble Fe(II) in the solution, the U(VI) removal was largely enhanced. The microbially-catalyzed U(VI) reduction resulted in an accumulation of solid-type U particles in and around the cells. Electron elemental investigations for the precipitates show that some background cations such as Ca and P were favorably coprecipitated with U. This implies that aqueous U tends to be stabilized by complexing with Ca or P ions, which easily diffuse and coprecipitate with U in and around the microbial cell.

• 한국재료학회지
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• 제28권5호
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• pp.301-307
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• 2018

A boron-doped diamond(BDD) electrode is attractive for many electrochemical applications due to its distinctive properties: an extremely wide potential window in aqueous and non-aqueous electrolytes, a very low and stable background current and a high resistance to surface fouling. An Ar gas mixture of $H_2$, $CH_4$ and trimethylboron (TMB, 0.1 % $C_3H_9B$ in $H_2$) is used in a hot filament chemical vapor deposition(HFCVD) reactor. The effect of argon addition on quality, structure and electrochemical property is investigated by scanning electron microscope(SEM), X-ray diffraction(XRD) and cyclic voltammetry(CV). In this study, BDD electrodes are manufactured using different $Ar/CH_4$ ratios ($Ar/CH_4$ = 0, 1, 2 and 4). The results of this study show that the diamond grain size decreases with increasing $Ar/CH_4$ ratios. On the other hand, the samples with an $Ar/CH_4$ ratio above 5 fail to produce a BDD electrode. In addition, the BDD electrodes manufactured by introducing different $Ar/CH_4$ ratios result in the most inclined to (111) preferential growth when the $Ar/CH_4$ ratio is 2. It is also noted that the electrochemical properties of the BDD electrode improve with the process of adding argon.

• 한국재료학회지
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• 제21권10호
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• pp.568-572
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• 2011

The preparation of $Y_2O_3$-doped $ZrO_2$ nanoparticles in Igepal CO-520/cyclohexane reverse micelle solutions is studied here. In this work, we synthesized nanosized $Y_2O_3$-doped $ZrO_2$ powders in a reverse micelle process using aqueous ammonia as the precipitant. In this way, a hydroxide precursor was obtained from nitrate solutions dispersed in the nanosized aqueous domains of a microemulsion consisting of cyclohexane as the oil phase, with poly (oxyethylene) nonylphenylether (Igepal CO-520) as the non-ionic surfactant. The synthesized and calcined powders were characterized by thermogravimetrydifferential thermal analysis (TGA-DTA), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The crystallite size was found to nearly identical with an increase in the water-to-surfactant (R) molar ratio. A FTIR analysis was carried to monitor the elimination of residual oil and surfactant phases from the microemulsion-derived precursor and the calcined powder. The average particle size and distribution of the synthesized $Y_2O_3$-doped $ZrO_2$ were below 5 nm and narrow, respectively. The TG-DTA analysis showed that the phase of the $Y_2O_3$-doped $ZrO_2$ nanoparticles changes from the monoclinic phase to the tetragonal phase at temperatures close to $530^{\circ}C$. The phase of the synthesized $Y_2O_3$-doped $ZrO_2$ when heated to $600^{\circ}C$ was tetragonal $ZrO_2$.

• Journal of Korean Society for Atmospheric Environment
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• 제14권E호
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• pp.27-40
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• 1998

The solubility characteristics of organic compounds were studied in terms of the extraction efficiency as a function of the polarity of the organic solvent, and the acidity of water in urban aerosol samples collected in University of East Anglia (UEA), Norwich, England. The extraction efficiency of organic compounds were evaluated with respect to the organic carbon, -nitrogen and -hydrogen by means of a wide range of solvent which include polar and nonpolar organic solvents as well as acids and alkaline water. In addition, after being dissolved in aqueous solution, the aqueous chemistry of organic compounds were studied in terms of the organic metal complexes in aerosol, which were studied with oxalic acid, copper, and zinc. The results of this study indicate that solubility characteristics of organic compounds depend on the polarity of the solvents and the acidity of the solvents. In particular, some organic compounds are water soluble, even though they are much smaller than acetone soluble fractions. In the comparison between polar organic solvent extraction and non- polar organic solvent extraction, it can be thought that significant fraction of organic compounds analysed in the aerosol samples, are polar organic compounds because of the higher extraction efficiencies of organic compounds in polar organic solvent extraction than in nonpolar organic solvent extraction. Regarding the study of the oxalic -metal complexes, it can be thought that most oxalic acids are present in the form of oxalic -copper complexes in the aerosols collected at UEA.

• Food Science and Biotechnology
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• 제18권3호
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• pp.724-731
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• 2009

Anthocyanins are considered one of the main color determinants in aged red wine. The anthocyanins in aged red wine made from 'Cabernet Gernischet' (Vitis vinifera L. cv.) grape were investigated by high performance liquid chromatography- electronic spray ionization- mass spectrometry (HPLC-ESI-MS) and their color presented in aqueous solution were evaluated using partial least square regression (PLS). The results showed that there were 37 anthocyanins identified in this wine, including 22 pyranoanthocyanins. The analysis of PLS indicated that different anthocyanins showed distinct color values: malvidin 3-O-(6-O-acetyl)-glucoside-4-vinylguaiacol (Mv3-acet-glu-vg) presented the highest color values, while malvidin 3-O-glucoside (Mv3-glu) showed least. Among the free non-acylated anthocyanins, peonidin 3-O-oglucoside (Pn3-glu) showed the highest color values; the coumarylated anthocyanins presented higher color values than their corresponding acetylated anthocyanins and parent anthocyanins; pyranoanthocyanins presented also higher color values than their original anthocyanins; the color of anthocyanins depended on their structure. This work will be helpful to reveal evolution in aged red wine.

• 공업화학
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• 제3권3호
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• pp.522-526
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• 1992

반응온도 $10^{\circ}C$하에서 수산화칼슘 수용액에 $CO_2$ 가스를 흡수시켜 탄산화반응을 행하였으며 비정질탄산칼슘의 생성과 전이과정을 조사하였다. 생성된 비정질탄산칼슘은 입경 약 $0.02{\sim}0.05{\mu}m$ 정도인 구형의 초미립자로서 소량의 부착수를 포함고, $HCO^-_3$ 이온이 일부 치환된 비화학양론적인 물질이었다. 이 물질은 매우 불안정하여 반응액 내에서 쉽게 안정한 calcite로 전이하게 되는데 반응액 내의 탄산기가 $CO_3^{2-}$ 이온 지배적인 경우에는 연쇄상 calcite로 전이하였고, $HCO^-_3$ 이온 지배적인 경우에는 능면체 calcite로 전이하였다. 그러므로 비정질탄산칼슘의 전이과정을 적절히 제어함으로써 탄산칼슘 입자의 형태와 크기를 조절하는 것이 가능할 것으로 생각된다.

• 한국응용과학기술학회지
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• 제35권4호
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• pp.1031-1037
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• 2018

수용성 비이온고분자인 Polyvinylalcohol (PVA), Polyvinylpyrrolidone (PVP), Hydroxypropyl cellusoe (HPC)와 iodine과의 착물 형성에 대한 계면활성제의 영향을 알아보기 위해 Sodiumdodecylsulfate을 포함하는 수용액에서 이들 사이의 반응을 수행하였다. PVP와 HPC에서 tri-iodide band의 적색 이동에 의하여 착물이 만들어졌다는 것을 알게되었고, PVA-iodine 착물에서는 500 nm 부근에서 고유의 특색있는 띠를 나타내었다. SDS 계면활성제의 존재는 PVA-iodine 착물의 파괴를 가져왔고, 고유의 푸른색도 사라지게 만들었다. 그러나 SDS 단량체는 PVP, HPC와 iodine의 착물 형성을 도와주는 경향을 나타내었다. 고분자 용액에서 겔이 만들어지는 것을 방해하는 n-propanol은 고분자-iodine 착물이 형성되는 것을 도와주었다. SDS가 있을 때와 없을 경우의 영향을 알아보기 위해 순수한 HPC와 HPC-iodine 착물을 만들고 이들의 성질을 조사하였다.